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Investment Securities Held to Maturity Securities by Type (Details) - USD ($) $ in Thousands | Sep. 30, 2020 | Dec. 31, 2019
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Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-maturity | $ 268,638 | $ 337,123
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain | 8,370 | 2,073
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss | (20) | (478)
Securities held to maturity, fair value | 276,988 | 338,718
US Government Agencies Residential Mortgage-backed Securities [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-maturity | 2,937 | 3,392
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain | 151 | 57
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss | 0 | 0
Securities held to maturity, fair value | 3,088 | 3,449
US Government Agency Debt Securities Commercial [Domain] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-maturity | 41,334 | 51,291
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain | 1,537 | 18
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss | 0 | (184)
Securities held to maturity, fair value | 42,871 | 51,125
Residential Mortgage Backed Securities [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-maturity | 171,100 | 229,667
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain | 5,646 | 1,377
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss | (19) | (294)
Securities held to maturity, fair value | 176,727 | 230,750
Obligations of U.S. Government-Sponsored Enterprises - Mortgage-Backed Securities - Commercial [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-maturity | 10,334 | 12,081
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain | 375 | 67
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss | 0 | 0
Securities held to maturity, fair value | 10,709 | 12,148
Obligations of States and Political Subdivisions [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-maturity | 42,133 | 40,092
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain | 661 | 554
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss | (1) | 0
Securities held to maturity, fair value | 42,793 | 40,646
Debt Security, Government, Non-US [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-maturity | 800 | 600
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain | 0 | 0
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss | 0 | 0
Securities held to maturity, fair value | $ 800 | $ 600

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- Definition Amount of investment in debt security measured at amortized cost (held-to-maturity). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=121553693&loc=d3e26610-111562 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 5 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27232-111563 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(6)) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 + Details
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- Definition Amount of accumulated unrecognized gain on investment in debt security measured at amortized cost (held-to-maturity). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 5 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27232-111563 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 5A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=121645371&loc=SL120269820-111563 + Details
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